1. Make the changes roger has mentioned (i guess you have done that already)

2. Now go to start->RUN and then type \\IP_ADDRESS (corresponding to your server)

3. It will ask you to authenticate, type login and password

4. Now try you perl script again

I tried to access the files from one of my computers on my network and i get Invalid argument at -e line 1.

Ignore the -e part as i was using command line perl. After I authenticated with the machine like the way i just explained i was able to access the file

Hope this helps.
I am not sure how windows's fileserver works with authentication and hence don't know ways to automate it.

On the other hand you can also map your network server to a drive and try to see if that works better for you?

update: if you don't know what path to use, just start->run type the ip_address\ and then browse to the directories. In windows explorer if you have turned on "address" bar then you can copy that into your open call. Just make sure you escpate \ with \\

How is the remote drive exported in the first place? Can you browse it at all? Why don't you open the explorer session, and manually browse to the location of the file under the NETWORK NEIGHBOURHOOD, and grab the fullpath name in the address bar. Then apply the double backslash bits to make it work?

Does the remote machine have an FTP server (and this file available through it)? If so, this task would be very easy with Net::FTP. But if not, as Roger says you need to determine how the file is shared by windows.